Traffic Infrastructure Research Articles

Evaluating the dynamic resilience of the multi-mode public transit network for sustainable transport

Improving multi-mode public transit resilience becomes crucial as urban traffic infrastructure gradually completes. This paper aims to build a dynamic resilience evaluation method and explore the resilience evolution process for multi-mode public transit. For establishing the resilience evaluation method, we considered both structural and functional indicators of the network. Then, we built a nonlinear load-capacity model and a cascading failure model to reflect the dynamic feature of resilience. Next, attack scenarios were designed according to the actual characteristics of the multi-mode public transit. Using the passenger flow data from Xi'an, we tested the impact of station capacity on the dynamic resilience results and analyzed the resilience evolution process. The results indicate that the network's resilience performance was the worst when the subway station was destroyed. Through adjusting the capacity control parameters, we found the best station capacity control parameter is α=0.5,β=0.4. Moreover, the sharply reducing intervals found in the results could help traffic managers improve transport efficiency while controlling costs.

Using multi-layer nested network to optimise spatial structure of tourism development between urban and rural areas based on population mobility

Under the bidirectional flow pattern of urban and rural factors, the tourism industry has become an important way to promote the vitality of urban and rural areas because of rural gentrification and city migration. By constructing a ‘node-link-setting’ networked land use model, this paper maps the tourism flow and geographic space networks, proposes a multi-layer nested network theory with spatial relevance from the mobility perspective to solve practical problems, such as urban–rural dual opposition and functional segmentation. We studied the high-precision mobile smart phone signalling data combined geographical data of Yichang, analysed the dynamic change process and comprehensive development mode characteristics of tourism attractions in 92 villages and towns through the social network analysis, compared tourism flow network changes in Yichang over time to construct a tourism flow network of Yichang, analysed the level and location of tourism nodes in the network and classified the tourist destinations to reveal the spatial-temporal evolution process and change the rule of the tourism flow network. The differences were compared by constructing traffic geography and infrastructure networks. The purpose is to propose guidance countermeasures for regional village unit tourism facility construction and industrial development and to maintain the integrity of spatial correlation and structural optimisation.

Long-Range Multi-Object Tracking at Traffic Intersections on Low-Power Devices

The next generation of intelligent traffic signal control systems needs multi-object tracking (MOT) algorithms that can track vehicles hundreds of meters away from traffic intersections. To facilitate the integration of long-range MOT into existing traffic infrastructure, the tracker must achieve a good balance of cost-effectiveness, accuracy, and efficiency. Although much progress has been made on deep-learning-based MOT for video, these approaches have limited applicability for edge deployment since deep neural networks typically require power-hungry hardware accelerators to achieve real-time performance. Furthermore, traffic cameras have a field of view limited to near the intersection. To address these shortcomings, we introduce a practical MOT framework that fuses tracks from a novel video MOT neural architecture designed for low-power edge devices with tracks from a commercially available traffic radar. The proposed neural architecture achieves high efficiency by using depthwise separable convolutions to jointly predict object detections alongside a dense grid of features at a single scale for spatiotemporal object re-identification. A simple and effective late fusion strategy is also presented where tracks of distant vehicles from a traffic radar are handed over to the video tracker within a region where the sensor fields of view overlap. Our video tracker is empirically validated on the UA-DETRAC video MOT benchmark for traffic intersections and the multi-sensor tracker is evaluated on video and radar data collected and labeled by the authors at an instrumented traffic intersection.

Urban traffic light scheduling for pedestrian–vehicle mixed-flow networks using discrete sine–cosine algorithm and its variants

This study addresses the traffic light scheduling problem for pedestrian–vehicle mixed-flow networks. A macroscopic model, which strikes an appropriate balance between pedestrians’ needs and vehicle drivers’ needs, is employed to describe the traffic light scheduling problem in a scheduling framework. The objective of this problem is to minimize the total network-wise delay time of vehicles and pedestrians within a given finite-time window, which is crucial to avoid traffic congestion in urban road networks. To achieve this objective, the present study first uses a well-known optimization solver called GUROBI to obtain the optimal solution by converting the problem into mixed-integer linear programming. The obtained results indicate the computational inefficiency of the solver for large network sizes. To overcome this computational inefficiency, three novel metaheuristic methods based on the sine–cosine algorithm are proposed. These methods are denoted by discrete sine–cosine algorithm, discrete sine–cosine algorithm with local search operator, and discrete sine–cosine algorithm with local search operator and memory utilization inspired by harmony search. Each of these methods is developed hierarchically by taking the advantages of previously developed method(s) in terms of a better search process to provide more accurate solutions and a better convergence rate. To validate all these proposed metaheuristics, extensive computational experiments are carried out using the real traffic infrastructure of Singapore. Moreover, various performance measures such as statistical optimization results, relative percentage deviation, computational time, statistical analysis, and convergence behavior analysis have been employed to evaluate the performance of algorithms. The comparison of the proposed SCA variants is done with GUROBI solver and other metaheuristics namely, harmony search, firefly algorithm, bat algorithm, artificial bee colony, genetic algorithm, salp swarm algorithm, and harris hawks optimization. Overall comparison analysis concludes that the proposed methods are very efficient to solve the traffic light scheduling problem for pedestrian–vehicle mixed-flow networks with different network sizes and prediction time horizons.

Urban Planning Impact on Mobility and Residential Satisfaction of Older People in Novi Sad

Social, political and economic changes have generated processes of revitalization of the built environment in post-socialist countries since the beginning of the 1990s; these changes are related to the physical structure of the city, its facilities and its functions, as well as the city landscape. Urban planning affects people’s quality of and way of life, as well as residential satisfaction with the built environment, especially that of older people, who make up a significant part of sustainable communities. This paper examines the residential satisfaction of older adults in terms of mobility—that is, their ability to move using facilities offered by public transportation and public places—in two neighborhoods of Novi Sad which have undergone the most extensive urban regeneration. This approach is different from the existing urban studies dealing with residential satisfaction, which makes it a contribution to the literature. Unlike previous studies—which have explored residential satisfaction at the level of accessibility to local facilities, safety in the urban environment and support from the environment—this paper also investigates the impact of movement in public space on the residential satisfaction of older people. The results show that the residential satisfaction of older people is low with regard to public transport, the arrangement of public spaces and traffic infrastructure.

Pedestrian Traffic Light Control with Crosswalk FMCW Radar and Group Tracking Algorithm.

The increased mobility requirements of modern lifestyles put more stress on existing traffic infrastructure, which causes reduced traffic flow, especially in peak traffic hours. This calls for new and advanced solutions in traffic flow regulation and management. One approach towards optimisation is a transition from static to dynamic traffic light intervals, especially in spots where pedestrian crossing cause stops in road traffic flow. In this paper, we propose a smart pedestrian traffic light triggering mechanism that uses a Frequency-modulated continuous-wave (FMCW) radar for pedestrian detection. Compared to, for example, camera-surveillance systems, radars have advantages in the ability to reliably detect pedestrians in low-visibility conditions and in maintaining privacy. Objects within a radar’s detection range are represented in a point cloud structure, in which pedestrians form clusters where they lose all identifiable features. Pedestrian detection and tracking are completed with a group tracking (GTRACK) algorithm that we modified to run on an external processor and not integrated into the used FMCW radar itself. The proposed prototype has been tested in multiple scenarios, where we focused on removing the call button from a conventional pedestrian traffic light. The prototype responded correctly in practically all cases by triggering the change in traffic signalization only when pedestrians were standing in the pavement area directly in front of the zebra crossing.

Traffic safety climate factors in explaining driving behaviours and traffic crash involvement: comparative study among male and female drivers

The study examined the explanatory power of Traffic Safety Climate factors in driving behaviours and the probability of traffic crash involvement among male and female drivers in China, taking into consideration different clusters of age. A total of 887 license drivers aged between 24 and 64 completed Chinese version of traffic climate scale, driving behaviours scale, and crash involvement. Multivariate regression analyses were conducted. The result established that male driver’s, reported high emotional engagement, driving violations and traffic crashes than female drivers. Perceived external affective demand (EAD) was more likely to be related to aberrant driving behaviours (ADB), but less likely to be related to positive driving behaviour (PDB) with young and middle-aged male drivers more affected. Perceived EAD was less likely to be associated with ADB and traffic crash involvement of female older drivers. The perceived internal requirement was positively related to PDB, but negatively related to ADB for both sexes with young females expressing high PDB and low probability of traffic crash involvement than male drivers. Perceived traffic system functionality (FUN) was negatively related to ADB, but positively related to PDB for both sexes with male drivers in all age brackets expressing more PDB. As a remedial measure, traffic authorities have to direct their attention towards the modification of traffic infrastructure designs.

Manajemen Pelayanan Penumpang Di Terminal Bus

This paper is to find out the use of bus terminals in serving passengers by using a descriptive method with a qualitative approach and using data collection techniques with interviews, 13 informants with research results Bus terminal utilization of passenger services namely Determining Terminal Locations, arranging terminal supporting facilities, Flow arrangement traffic in the terminal supervision area, scheduling of officers in the terminal and evaluation of the terminal operating system. Obstacles encountered in passenger service to the effectiveness of using bus terminals include traffic facilities and infrastructure are still limited, traffic management has not functioned optimally, passenger public transport services are inadequate. Efforts carried out in the service effectiveness of bus terminal utilization on passenger services, namely Improving the waiting area service and the flow of public vehicles within the terminal, improving service in the arrival and departure of vehicles according to a predetermined schedule, Collecting passenger terminal services and Increasing the current flow settings crossing in the terminal surveillance area

Microbiological Characteristics of Some Stations of Moscow Subway.

Simple SummaryPublic transport facilities, including subway systems, provide the most suitable conditions for the transfer of microorganisms between people and the environment, contributing to the pathogenic potential of the urban habitat. Investigation of microbiome diversity and description of its characteristic properties, e.g., antibiotic-resistance profiles, leads to understanding of these interactions. In this study, we aimed to conduct an extended analysis of the bioaerosol and surface microbiome of the Moscow subway, using 16S rRNA gene sample sequencing and classical microbiology methods. The microbiomes of two subway stations (Novokosino and Cherkizovskaya) were reconstructed which differ in terms of passenger traffic and duration of exploitation. It was shown that most bacterial genera were ubiquitous; however, the unique genera were presented in aerosol samples. The relatively older Cherkizovskaya station possessed greater diversity in antibiotic resistance among the identified microorganisms compared to Novokosino station. We also provided a comparative analysis of these results with the previously published data, which allowed us to identify the distribution of microorganisms associated with the human microbiome and the environment regardless of the seasonal fluctuations. The obtained results provide valuable information on the diversity of bacterial communities in the Moscow subway, one of the most socially important facilities in metropolitan areas.The subway is one of the most actively used means of transport in the traffic infrastructure of large metropolitan areas. More than seven million passengers use the Moscow subway every day, which promotes the exchange of microorganisms between people and the surrounding subway environment. In this research, a study of the bacterial communities of two Moscow subway stations was conducted and the common subway microbiome was determined. However, there were differences in microbiological and antibiotic-resistance profiles, depending on the station. The station’s operational period since opening correlated with the taxonomic diversity and resistance of the identified bacteria. Moreover, differences between aerosol and surface bacterial communities were found at the two subway stations, indicating the importance of diversified sampling during the microbiome profiling of public areas. In this study, we also compared our data with previously published results obtained for the Moscow subway. Despite sample collection at different stations and seasons, we showed the presence of 15 common genera forming the core microbiome of the Moscow subway, which represents human commensal species, as well as widespread microorganisms from the surrounding environment.

Citizen Science for Traffic Monitoring: Investigating the Potentials for Complementing Traffic Counters with Crowdsourced Data

Traffic counts are among the most frequently employed data to assess the traffic patterns and key performance indicators of next generation sustainable cities. Automatised counting is often based on conventional traffic monitoring systems such as inductive loop counters (ILCs). These are costly to install, maintain, and support. In this paper, we investigate the possibilities to complement and potentially replace the existing traffic monitoring infrastructure with crowdsourcing solutions. More precisely, we investigate the capabilities to predict the ILC-obtained data using Telraam counters, low-cost camera counters voluntarily employed by citizens and freely accessible by the general public. In this context, we apply different exploratory data analysis approaches and demonstrate a regression procedure with a selected set of regression models. The presented analysis is demonstrated on different urban and highway road segments in Slovenia. Our results show that the data obtained from low-cost and easily accessible counters can be used to replace the existing traffic monitoring infrastructure in different scenarios. These results confirm the prospective to directly apply the citizen engagement in the process of planning and maintaining sustainable future cities.

The effects of visual landscape and traffic type on soundscape perception in high-rise residential estates of an urban city

In dense urban cities with high-rise estates where large population of residents live in close proximity, the increasing noise exposure in soundscapes due to traffic noise, construction and other undesirable anthropophony in urban lived environments may cause adverse effects on the wellbeing of residents. In this study, soundscapes around such urban spaces are investigated using Singapore as a case study. This study aims to discover the current conditions of soundscapes around such spaces and whether traffic and landscape features have a sizeable effect on soundscape perception, as well as to develop a predictive model using soundscape indicators based on acoustics, psychoacoustics, and audio features. The results show that the soundscapes in the selected urban city’s heartlands are generally dominated by traffic (40%) and biophonic (36%) sources. This study identifies the significant effects of both traffic conditions and landscape features that affect soundscape perception. A predictive model is developed based on identified objective indicators and an alternate method to derive the total mask duration of positive sound events. The visibility of roadways and vehicles correlates negatively with soundscape perception and reaffirms the effects of road visibility on noise annoyance. However, light traffic conditions do not adversely affect the soundscape perception as compared to heavy traffic, suggesting tolerance for light traffic by the participants in residential settings. Thus, the present study recommends that urban planners should take into consideration the type of traffic infrastructure when planning residential developments.

Using hydro‐morphological assessment parameters to estimate the flood‐induced vulnerability of watercourses ‐ a methodological approach across three spatial scales in Germany and the Czech Republic

AbstractIn addition to their ecological importance, rivers and streams have always been used in diverse ways by humans, resulting in the development of settlements and their connected built environments along many of the world's watercourses. During heavy rainfall, buildings, traffic infrastructure and water‐related infrastructure are exposed to potential hazards in the form of (flash) floods. In contrast to near‐natural watercourses, anthropogenically modified channels in urban areas are particularly susceptible to damage by flooding. Previous damage assessments have highlighted the need to forecast such damage to watercourses in order to identify critical areas and justify the selection and expansion of adaptation measures. Within the scope of the current study, we have developed a method based on the hydro‐morphological properties of watercourses to make transferable estimates of the economic damage potential based on ecologically‐relevant parameters. Using a scale‐specific cause‐effect analysis, we have identified characteristics of the watercourse type and adjacent structures as well as construction‐related properties of reinforcements that can increase the damage potential during flooding. In this way, we are able to show that several influencing factors determine the vulnerability of watercourses: in addition to the specific longitudinal gradient and size (macroscale) of various watercourse types, damage‐relevant boundary conditions in watercourse sections (mesoscale) and the resistance of typical bed and bank constructions are also important, reflecting the specific structural conditions. Taking rivers in Germany and the Czech Republic as case studies, in the following, we review the local identification of critical areas and describe the necessary data management. The presented “Hydro‐morphological based Vulnerability Assessment‐Concept (HyVAC)” can contribute to the flood damage prevention at watercourses by utilizing existing basic data to the greatest possible extent and thus is suitable for preliminary investigations according to the EC Flood Risk Management Directive.

Damage to Residual Trees in Thinning of Broadleaf Stand by Mechanised Harvesting System

This research was conducted to determine the cause, intensity and location of damage (stem, butt end, root collar, root) and the extent of damage to standing trees during felling and processing by an harvester and timber extraction by a forwarder (cut-to-length system). The research was conducted in the central part of the Republic of Croatia in the Management Unit (MU) “Bjelovarska Bilogora” during the thinning of Subcompartment 14b, area of 18.28 ha, in the stand of hornbeam (Carpino betuli—Quercetum roboris fagetosum Rauš 1975), age 70, and of Subcompartment 14c, area of 9.07 ha, in a stand of common beech (Carici pilosae—Fagetum Oberdorfer 1957) aged 79 years. The thinning intensity was 12.13% in Subcompartment 14b and 13.72% in Subcompartment 14c. Field measurements were carried out on sample plots—the first time in 2017 to determine the intensity and characteristics of the damage to standing trees with regard to the cause of the damage (harvester or forwarder), and the second time in 2018 to determine the overall intensity and features of the damage to standing trees after finishing harvesting operations. For all trees remaining in the stand after the harvesting operations, the following were determined: tree species, diameter at breast height (DBH), the position of the tree in the stand depending on the forest traffic infrastructure, and—if damaged—cause of damage, type of damage, the position of damage on the tree, and dimensions of damage. The intensity of the damage was expressed by the ratio of damaged and undamaged trees, with a detailed analysis of bark damage (squeezed-bark damage and peeled-bark injuries). The results of the research indicate the highest prevalence of peeled-bark injuries. In relation to the total number of standing trees, trees with peeled-bark injuries were more represented in Subcompartment 14c (39%) than in Subcompartment 14b (33%). In Subcompartment 14b, the harvester and the forwarder damaged an equal number of trees, while in Subcompartment 14c, the harvester damaged 59% of the damaged trees. In both subcompartments, an average of 83% of (peeled bark) injuries were up to 1.3 m above the ground. In both subcompartments, the most common (67%) were injuries up to 100 cm2 in size, for which many authors claim the tree can heal by itself. Given the increasing use of harvester-forwarder systems in deciduous stands and research results that indicate possible damage to standing trees, it is necessary to pay attention to all phases of planning and execution of timber harvesting operations, thus minimising negative effects.

Reshaping the Intelligent Transportation Scene: Challenges of an Operational and Safe Internet of Vehicles

In the emerging era of transportation, the Internet of Vehicles envisions a large ecosystem where vehicles, traffic infrastructure, smart city sensors, and citizens will interoperate, providing safe and fast transportation services. How close are we to realizing this concept?

Signalized Intersection Control in Mixed Autonomous and Regular Vehicles Traffic Environment—A Critical Review Focusing on Future Control

The recent advancement in industrial technology has offered new opportunities to overcome different problems of stochastic driving behavior of humans through effective implementation of autonomous vehicles (AVs). Optimum utilization of driving behavior and advanced capabilities of the AVs has enabled researchers to propose autonomous cooperative-based methods for signalized intersection control under an AV traffic environment. In the future, AVs will share road networks with regular vehicles (RVs), representing a dynamic mixed traffic environment of two groups of vehicles with different characteristics. Without compromising the safety and level of service, traffic operation and control of such a complex environment is a challenging task. The current study includes a comprehensive review focused on the signalized intersection control methods under a mixed traffic environment. The different proposed methods in the literature are based on certain assumptions, requirements, and constraints mainly associated with traffic composition, connectivity, road infrastructures, intersection, and functional network design. Therefore, these methods should be evaluated with appropriate consideration of the underlying assumptions and limitations. This study concludes that the application of adaptive traffic signal control can effectively optimize traffic signal plans for variations of AV traffic environments. However, artificial intelligence approaches primarily focusing on reinforcement learning should be considered to better utilization of the improved AV characteristics.

KEY MICROECONOMICS NOTES: “STEPS FOR GEVGELIJA AERODROME INFRASTRUCTURE DEVELOPMENT INVESTMENT”

As in life, so in the traffic system, it revolves around balance. The growth of the economy as a result of the balanced development of the transport system, which analyzes the concept, importance, strategy, and, the meaning of inflation as one of the elements for entry into the European Union, requires an explanation of the environmental, economic and social impact. In order to explain the impact of inflation on the transport system in the Republic of Macedonia, we start from the cost benefit analise, as well as its elaboration in connection with the concept of economic growth. The dominant explanation for this trend is the continuous upward trend in economic growth necessary for implementation and entry into the European Union. The purpose of balancing in this essay is to determine the potential of aerodrome infrastructure transformation, that is, to determine which sectors and what economic growth means at the national level with the goal of building the traffic aerodrome infrastructure. To explain the necessary evolution to sustainable growth, the theory of equilibrium or balance will be used to explain the necessary progress at the national level. The significance of this research is the improvement of the co-operational aerodrome infrastructure in the country as a need for the development of the country in the process of implementation of the reforms of the European Union. Together with related strategies and initiatives that affect Macedonia, the aim of this thesis is to determine how and in what way Macedonia participates in the transformation of its economy and contributes to the common European economy.

Position-Dependent Fundamental Diagram Parameterizations in Traffic Flow Modeling on Highways

Model-based reproduction of traffic flow behavior is essential in making predictions about the development of traffic situations. Accurate knowledge of traffic behavior is not only essential for traffic control infrastructure but also provides beneficial information to individual vehicles with regard to connected or autonomous vehicles. Typically traffic flow models are based on partial differential equations using fixed parameterization over the examined position. Within the scope of this work, the benefits of a position-dependent parameterization of the fundamental diagram are shown using a tested traffic model that can be used in real-time applications with few discretization intervals. The resulting improvements are validated using highway detector measurements for two real traffic situations over a horizon of several kilometers. The result of this work proves increased simulation performance in traffic flow modeling if position-dependent parameters are available or observable.

LANDSLIDE SUSCEPTIBILITY ASSESSMENT OF THE CITY OF KARLOVAC USING THE BIVARIATE STATISTICAL ANALYSIS

A preliminary landslide susceptibility analysis on a regional scale of 1:100 000 using bivariate statistics was conducted for the City of Karlovac. The City administration compiled landslide inventory used in the analysis based on recorded landslides from 2014 to 2019 that caused significant damage to buildings or infrastructures. Analyses included 17 geofactors relevant to landslide occurrence and classified them into four groups: geomorphological (elevation, slope gradient, slope orientation, terrain curvature, terrain roughness), geological (lithology-rock type, proximity to geological contacts, proximity to faults), hydrological (proximity to drainage network, proximity to springs, proximity to temporary, permanent and to all streams, topographic wetness) and anthropogenic (proximity to traffic infrastructure, land cover using two classifications). Five scenarios were defined using a different combination of geofactors weighted by the Weights-of Evidence (WoE) method, resulting in five different landslide susceptibility maps. The best landslide susceptibility map was selected upon the results of a ROC curve analysis, which was used to obtain success and prediction rates of each scenario. The novelty in the presented research is that a limited amount of thematic data and an incomplete landslide inventory map allows for the production of a preliminary landslide susceptibility map for usage in spatial planning. Also, this study provides a discussion regarding the used method, geofactors, defined scenarios and reliability of the results. The final preliminary landslide susceptibility map was derived using ten geofactors, which satisfied the pairwise CI test, and it is classified in four zones: low landslide susceptibility (57.05% of the area), medium landslide susceptibility (20.63% of the area), high landslide susceptibility (13.28% of the area), and very high landslide susceptibility (9.03% of the area), and has a success rate of 94% and a prediction rate of 93% making it a highly accurate source of preliminary information for the study area.

Autonomous Vehicle Design in Lean Product Development Processes for Value Stream Map

The global automotive industry is giving a difficult and common test in order to create advanced life models in the near future plans or scenarios that include current autonomous vehicle technologies. Therefore, the main purpose of the research is to comparatively evaluate the impact of autonomous vehicle technologies, which are newly included in the automotive manufacturing industry under sustainable competition, on lean product development processes, value acquisition and preservation, in different organizational structures in the approach. Although mergers or brand acquisitions in the global automotive industry create joint R & D (Research Development) or joint new P & D (Product Development) process structures for the development of autonomous vehicle technologies, heavy competition continues in the market. These new processes create different needs for the merger and partnership of the renewed traffic infrastructures under national and international regulations, and for the implementation of the new autonomous life model. Firm and brand marriages, mergers or acquisitions in today’s automotive industry have ensured the high diffusion of lean product development processes under the stream of value creation or preservation carried out specific to the company under competition. Brand mergers in automotive industry companies struggling to survive under high competition create new work disciplines, professions, and engineering flow steps in lean product development processes. However, lean product development processes driven by technological innovation under simplification have resulted in the integration of parts and systems within the autonomous vehicle design structure, as well as creating new interdisciplinary value streams or different stakeholders. Therefore, the research revealed the significant effects of lean product development processes on the value stream in the automotive industry, on the mixed and lean product development process structure formed by new or existing vehicle systems (conventional vehicle) under the penetration of each existing and new discipline. This research compares the efficient operation steps of the process stakeholders in the autonomous vehicle design parts or systems containing innovation and new technology together with the value stream in the lean product development process, and the new process stakeholder’s business-oriented global and local automotive industry companies. New autonomous vehicle technologies, together with their unique software, hardware and development analysis, have been involved in the lean product development process with their interdisciplinary studies or expertise. Therefore, the study firstly focused on the technologies in environmental use together with the new basic features of autonomous vehicles, and then examined in depth the new or existing disciplines and interdisciplinary basic structure that these innovations affect under the value stream in the lean product development process. In addition, micro-level results and recommendations were shared, shedding light on how autonomous vehicle levels will create changes in the new product development process.

Crack control for repair and strengthening of reinforced concrete structures using the multi-cracking behaviour of Ultra-high Performance Fibre Reinforced Shotcrete (UHPFRSC)

Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) is an innovative material for the repair and/or strengthening of reinforced concrete structures. In the field of traffic infrastructure, the outstanding mechanical properties are used as a protective surface layer and to increase the load capacity of the structure. UHPFRC is characterised by a dense granular structure and correspondingly high resistance against chloride attack. The material is typically applied as cast in-situ concrete. To optimise implementation of the strengthening and repair method, the UHPFRC is applied as sprayed concrete, so-called Ultra-High Performance Fibre Reinforced Shotcrete (UHPFRSC). The research aims to increase the service life of damaged and/or overloaded structures. Crack widths in the UHPFRSC layer must be limited to avoid migration of chlorides. The thin UHPFRSC layer provides crack distribution and control of localised macro cracks in the existing reinforced concrete structure. The fibres in the Ultra-High Performance Shotcrete (UHPSC) allows for limiting the crack width to 50 µm. When the UHPFRSC is applied on cracked reinforced concrete, it can be assumed that multi-cracking in the UHPFRSC surface layer will provide a chloride-dense layer equivalent to a coating. Under load, the two layers - UHPFRC and RC - act as a composite. For structural analysis, a particular focus must be placed on the interaction between cementitious materials. In addition, the pre-damage and pre-loading of the existing structure will influence the structural behaviour and crack formation. The paper presents the results of bending tests of UHPFRC - RC composite elements. The investigation shows the outstanding crack control behaviour of UHPFRSC. Based on this investigation, an analytical model will be provided, and a calculation of the crack widths will be derived. The research presents a central aspect of a large interdisciplinary research project at Munich University of Applied Science, called i-SCUP.